Pipe wrench



May 30, 1944.

c. D. STITELER PIPE WRENCH Filed Sept. 8 1941 ATTORN IYS Patented May 30, 1944 UNITED STATES PATENT OFFICE PIPE WRENCH Charles D. Stiteler, Gothenburg, Nebr.

Application September 8, 1941, Serial No. 410,066

1 Claim.

My invention relates to pipe wrenches, and has among its objects and advantages the provision of an improved self-locking wrench.

In the accompanying drawing:

Figure 1 is a side elevational view of a wrench in accordance with my invention;

Figure 2 is a rear view of a portion of the wrench;

Figures 3, 4, 5, 6 and 7 illustrate the action of the wrench under difierent operating conditions; and

Figure 8 is a view similar to Figure 1 illustrating the manner in which the self-locking wrench of Figure 1 may be converted into a wrench having the action of the so-called Stillson type.

In the embodiment selected to illustrate my invention, the wrench includes a handle part Ill provided with a grip 12 at one end, with its opposite end fashioned to provide a jaw I4 provided with a toothed face l6 of curved configuration. Upon the handle part II] I mount a swivel casting 18 having walls 20 between which the grip part I is positioned. An opening 22 is provided in the grip part [0 for the reception of a pin 24 which also extends through openings 26 in the walls 20. A head 28 is formed on one end of the pin 24, while the opposite end of the pin is provided with a transverse bore for the reception of a cotter pin 30. Thus the swivel casting I8 is pivotally connected with the handle part I0 through the medium of the pin 24.

A movable jaw 32 includes the usual toothed face 34 and is provided with a shank 36 extending between the walls 20 and threaded at 38 for the reception of the nut 40 which is accommodated in the openings 42 in the two walls 20. Thus the jaw 32 may be adjusted towards and away from the jaw I4 through rotation of the nut 40 in the manner of conventional wrenches. To the handle part I0 I fixedly secure one end of a spring 44 having its other end arranged in pressure relation with the nut 40 for normally urging the jaw 32 to the position of Figure 1.

Walls 20 are provided with aligned openings 46 for the reception of the screw 24 which may be transferred to these aligned openings and passed through the second. opening 48 in the handle part [0 closely adjacent the jaw l4. Figure 8 illustrates the pin 24 passed through the openings 46 and 48, at which time the wrench takes the general arrangement of parts corresponding to the original Stillson wrench. Referring to Figure 1, the points of the teeth I6 are arranged in an are having its radial center located at the point 50 which is somewhat to the right of the axis of the pin 24 when the wrench is positioned according to Figure 1. Line 52 indicates the curvature of the toothed face l6, while the line 54 illustrates the path of the jaw M as it is pivoted about the axis of the pin 24.

With the wrench adjusted according to Figure 8 which corresponds to the Stillson type of construction, the stock 56 which is positioned between the jaws l4 and 32 is gripped'firmly by the jaws when located intermediate the ends thereof or toward their outer ends. When positioned closely adjacent the shank 36, the jaws have very little gripping action on the stock, and the axis of the pin 24 in the arrangement of Figure 8 lies to the left of the points of contact between the stock 56 and the jaws l4 and 32. The stock 56 will therefore exert separating pressure on the two jaws at points located to the right of the axis of the pin 24 so that the jaws will tend to separate. In other words, the jaw l4 will tend to pivot in the direction of the arrow 58 so as to defeat any locking action of the wrench on the stock.

With the parts adjusted according to Figure 1, the stock 60 may be positioned closely adjacent the shank 36, and the points of contact between the stock and the jaws I4 and 32 are located considerably to the left of the axis of the pin 24 so as to tend to pivot the jaw in the direction of the arrow 62 which causes the wrench to look upon the stock 60.

In operation, the jaws l4 and 32 are swung open and the stock 60 is placed well within the wrench, after which the jaws are drawn down upon the stock as far as possible through the medium of the nut 40. Figure 3 illustrates the jaws sprung open and the stock 60 placed in position. Pressure is then applied to the handle and the jaw I4 is forced against the stock, which brings the wrench part and the stock to the relative position illustrated in Figure 4. Under such conditions, the wrench is eifectively locked on the stock 60. Figure 5 illustrates the relative positions of the wrench part and the stock when the handle part In is pulled in the opposite direction. The stock 60 is rolled in the jaws l4 and. 32 until it takes a position slightly to the other side of the axis of the pin 24 as the shank 36 abuts the handle part I 0. A strong jolt would be necessary to remove the wrench from the stock even with the parts positioned according to Figure 5. Figure 6 illustrates the arrangement of the jaws and the stock when the handle is again moved in a forward direction. The stock 60 is again rolled towards the shank 36 and assumes the position of Figure 4. To remove the wrench from the stock 60, pressure must be applied to the back of the upper jaw and the handle part I0 pulled backwardly at which time the jaw parts and the stock will take the relative positions of Figure 7, at which time the wrench may readily be removed through loosening of the jaw part 32 through adjustment of the nut 40.

I claim:

A pipe wrench comprising a handle having a first jaw at one end thereof, a second jaw having a threaded shank, a swivel casting having a pivotal connection with said handle, said pivotal connection including aligned openings in i5 said swivel casting and the handle and a pin passing through said aligned openings, said swivel casting and said handle being provided with second co-operable openings for the reception of said pin to provide a shifted pivotal connection between the swivel casting and said handle, and means coacting with said swivel casting and said threaded shank for adjusting the second jaw relatively to the first jaw, said first jaw having a curvature concentric about an axis located to one side of the axis of said pivotal connection and in a plane passing through the axis of the pivotal connection substantially at right angles to the longitudinal axis of the handle.

CHARLES D. STITELER. 

